Minecraft Turtle: Diagonal Hallway

--[[
    2013 (c) psychedelixx
    Minecraft Turtle: Diagonal Hallway
    2013-05-24

    Digs a diagonal hallway and places missing ground blocks and torches.

    Usage:
    - use turtle and type "label set <name>"
      (to give your turtle an unique name so it remembers its programs)
    - type "pastebin get d9CBNDCz diagonal"
    - place solid blocks in slot 16 (lower right corner)
    - place torches in slot 15 (left of slot 16)
    - type either "diagonal left ###" or "diagonal right ###" (replace ### with a number)
--]]

function move()
    print(turtle.getFuelLevel())
        if turtle.getFuelLevel() < 5 then
                turtle.refuel()
        end
        if not turtle.detectDown() then
                turtle.select(16)
                turtle.placeDown()
        end

        while not turtle.forward() do
                turtle.dig()
        end
end

local args = { ... }
if #args < 2 then
  print( "Usage: diagonal <direction> (right / left) <limit>" )
  error()
end
dir = args[1]
limit = tonumber(args[2])

if turtle.getFuelLevel() == 0 then
    turtle.refuel()
end

if turtle.getFuelLevel() == 0 then
    print("I need fuel!")
else
    print("======== 2013 (c) psychedelixx ========")
    print("Let's go!")

    move()
    turtle.digUp()
    if dir == "left" then
        turtle.turnLeft()
    else
        turtle.turnRight()
    end
    move()
    turtle.digUp()
    if dir == "left" then
        turtle.turnRight()
    else
        turtle.turnLeft()
    end
    while turtle.detect() do turtle.dig() end
    turtle.up()
    while turtle.detect() do turtle.dig() end
    if dir == "left" then
        turtle.turnLeft()
    else
        turtle.turnRight()
    end
    while turtle.detect() do turtle.dig() end
    turtle.down()
    move()
    if dir == "left" then
        turtle.turnRight()
    else
        turtle.turnLeft()
    end

    torchCount = 0
    while turtle.getFuelLevel() > 0 and limit > 0 do
        print("")
        print("Remaining: " .. limit)
        print("Fuel: " .. turtle.getFuelLevel())

        move()
        turtle.digUp()
        while turtle.detect() do turtle.dig() end
        turtle.up()
        while turtle.detect() do turtle.dig() end

        if torchCount%4 == 0 then
            turtle.select(15)
            turtle.place()
        end

        if dir == "left" then
            turtle.turnLeft()
        else
            turtle.turnRight()
        end
        while turtle.detect() do turtle.dig() end
        turtle.down()
        move()

        if dir == "left" then
            turtle.turnRight()
        else
            turtle.turnLeft()
        end

        limit = limit-1
        torchCount = torchCount + 1
    end
    move()
    turtle.digUp()
end